Method

1. For the potato and prawn cakes: preheat the oven to 190C/gas 5.

2. Bake the sweet potatoes in the oven until completely tender. How long this takes depends on the size of the potatoes. Leave until they are cool enough to handle and remove the flesh from the skin (discard the skin).

3. Heat 1½ tablespoons of the oil in a frying pan and sauté the onion, garlic and chilli until soft but not coloured. Add the cumin and cook for another couple of minutes, just to release the fragrance.

4. Mash the sweet potato flesh with plenty of salt and pepper, add the prawns and the coriander. Add the cooked onion and chilli mixture and mix well. Add the flour and incorporate it. Taste some of the mixture for seasoning the put it in the fridge so that it can firm up a little.

5. With floured hands, form the mixture into little balls and pat down. The mixture will be very sticky but it will work once you get it into the pan. Make sure each cake has a light coating of flour. If you're making these in advance (and it's a good idea to) then put the little cakes on a baking tray, cover with cling film and keep in the fridge.

6. For the raita: squeeze some water out of the cucumber by putting it in a j-cloth. It's also best to make this not more than an hour before serving as water does leach out of the cucumber making the yoghurt runny. I can never be bothered to go through the process of salting the cucumber just for a bowl of raita, though. Mix the cucumber with all the other raita ingredients and stick in the fridge until you need it.

7. Heat some of the oil in a frying pan and fry the potato and prawn cakes until golden on both sides and hot through. You'll have to do them in batches and treat them gently as they are quite fragile. Add more oil as you need it.

8. Serve the potato and prawn cakes hot from the frying pan with the raita and mango chutney.